# dns-mx-via-dnssb

> dns-mx-via-dnssb is a paid API for AI agents from dns.intel.rallylive.ca, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-21).

Retrieves MX records for a domain using DNS.SB as the DNS-over-HTTPS resolver, returning records, TTL, response code, DNSSEC validation status, and resolver latency.

## Facts

- Endpoint: GET https://dns.intel.rallylive.ca/dns/mx/via/dnssb?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/dns-mx-via-dnssb-80a1add4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_3ersr-aC4R3ihE7dJO0Gk

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability dns-mx-via-dnssb-80a1add4
```

Example prompt: Can you look up the MX records for example.com using DNS.SB and tell me the mail servers, their TTL, whether DNSSEC was validated, and how fast DNS.SB responded?

## When to prefer this

Choose this endpoint when you specifically need MX records as seen by the DNS.SB resolver (useful for comparing resolver-specific answers, detecting split-horizon DNS, or checking propagation to this particular resolver). Prefer over generic DNS tools when DNSSEC validation status and resolver latency are important signals alongside the record data.

## Known failure modes

- Domain does not exist — returns NXDOMAIN response code with no records
- Resolver failure — returns SERVFAIL with no records
- Domain has no MX records — returns NOERROR with empty answer set
- Invalid domain name input — may return error or SERVFAIL
- Payment not processed — request rejected before DNS lookup is performed

## How this service works

MX records for a domain as answered by DNS.SB (DNS over HTTPS): the records, TTL, response code (NOERROR/NXDOMAIN/SERVFAIL), whether the resolver validated DNSSEC, and the resolver's answer time. Compare resolvers to spot propagation lag, filtering or split-horizon answers. $0.01 per lookup.

## Output

Returns the MX records (hostname and priority) for the queried domain, the record TTL, the DNS response code (NOERROR, NXDOMAIN, or SERVFAIL), whether DNS.SB validated DNSSEC for the response, and the resolver's answer time in milliseconds.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/dns-mx-via-dnssb-80a1add4/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from dns.intel.rallylive.ca](https://www.zero.xyz/host/dns.intel.rallylive.ca/llms.txt)